
  // This is called with the results from from FB.getLoginStatus().
  function statusChangeCallback(response) {
    console.log('statusChangeCallback');
    console.log(response);
    // The response object is returned with a status field that lets the
    // app know the current login status of the person.
    // Full docs on the response object can be found in the documentation
    // for FB.getLoginStatus().
    if (response.status === 'connected') {
      // Logged into your app and Facebook.
      testAPI();
    } else if (response.status === 'not_authorized') {
      // The person is logged into Facebook, but not your app.
      document.getElementById('status').innerHTML = 'Please log ' +
        'into this app.';
    } else {
      // The person is not logged into Facebook, so we're not sure if
      // they are logged into this app or not.
      document.getElementById('status').innerHTML = 'Please log ' +
        'into Facebook.';
    }
  }

  // This function is called when someone finishes with the Login
  // Button.  See the onlogin handler attached to it in the sample
  // code below.
  function checkLoginState() {
    FB.getLoginStatus(function(response) {
      statusChangeCallback(response);
    });
  }

    function fb_init(app_id) {
	  window.fbAsyncInit = function() {
	  FB.init({
		appId      : app_id,
		cookie     : true,  // enable cookies to allow the server to access 
							// the session
		xfbml      : true,  // parse social plugins on this page
		version    : 'v2.0' // use version 2.0
	  });

	  // Now that we've initialized the JavaScript SDK, we call 
	  // FB.getLoginStatus().  This function gets the state of the
	  // person visiting this page and can return one of three states to
	  // the callback you provide.  They can be:
	  //
	  // 1. Logged into your app ('connected')
	  // 2. Logged into Facebook, but not your app ('not_authorized')
	  // 3. Not logged into Facebook and can't tell if they are logged into
	  //    your app or not.
	  //
	  // These three cases are handled in the callback function.

	  FB.getLoginStatus(function(response) {
		statusChangeCallback(response);
	  });

	  };

	  // Load the SDK asynchronously
	  (function(d, s, id) {
		var js, fjs = d.getElementsByTagName(s)[0];
		if (d.getElementById(id)) return;
		js = d.createElement(s); js.id = id;
		js.src = "//connect.facebook.net/en_US/sdk.js";
		fjs.parentNode.insertBefore(js, fjs);
	  }(document, 'script', 'facebook-jssdk'));
	}
	
	function fb_post() {
		var params = {};
		params['message'] = 'The message';
		params['name'] = 'Name';
		params['description'] = 'this is a description';
		params['link'] = 'http://www.somelink.com/page.htm';
		params['picture'] = 'http://www.somelink.com/img/pic.jpg';
		params['caption'] = 'Caption of the Post';
		 
		FB.api('/me/feed', 'post', params, function(response) {
		  if (!response || response.error) {
			// an error occured
			alert(JSON.stringify(response.error));
		  } else {
			// Done
			alert('Published to stream');
		  }
		});
	}
	
	
  // Here we run a very simple test of the Graph API after login is
  // successful.  See statusChangeCallback() for when this call is made.
  function testAPI() {
    console.log('Welcome!  Fetching your information.... ');
    FB.api('/me', function(response) {
      console.log('Successful login for: ' + response.name);
      document.getElementById('status').innerHTML =
        'Thanks for logging in, ' + response.name + '!';
    });
  }
